function assert(condition, message) {
  if (!condition) {
    throw new Error("[vue-router] " + message);
  }
}

function warn(condition, message) {
  if ("development" !== "production" && !condition) {
    typeof console !== "undefined" && console.warn("[vue-router] " + message);
  }
}

function isError(err) {
  return Object.prototype.toString.call(err).indexOf("Error") > -1;
}
